Male plug assembly incorporating power supply

ABSTRACT

A power supply is incorporated in a male plug assembly at one end of a line cord. The male plug assembly is provided with means for preventing said assembly from abutting against a wall when said male plug is received in a female receptacle in said wall. The aforesaid means maintains an air space between the wall and the assembly thereby enabling convection air currents to dissipate the heat produced by the power supply.

United States Patent n Ferro et al.

[ Apr. 29, 1975 MALE PLUG ASSEMBLY INCORPORATING POWER SUPPLY [75]Inventors: Armand P. Ferro: Nancy D. Fitzroy.

both of Schenectady. NY.

[73] Assignee: General Electric Company.

Schenectady. NY.

22 Filed: May 30. 1974 2| Appl.No.:474,669

(52] US. Cl. 339/ll2 R; 339/63 Rzl76 R [St] Int. Cl l-l0lr 13/00 [58]Field of Search 339/1 [2 R. 42. 62. 63 R. 339/63 M. [76 R. [95 R. 195 M.196 R. I96 M [56] References Cited UNITED STATES PATENTS 2.9l5.732l2/l959 Pifcr 339/62 X 5/l970 Dcgactano 339/42 l2/l97l Eckcrt 339/42 XPrimary E.\'uminvr-Roy Lake Assistant E.\'uminerDeWalden W. JonesAttorney, Agent. or Firm-Jack E. Haken; Joseph T. Cohen; Jerome C.Squillaro [57] ABSTRACT A power supply is incorporated in a male plugassembly at one end ofa line cord. The male plug assembly is providedwith means for preventing said assembly from abutting against a wallwhen said male plug is received in a female receptacle in said wall Theaforesaid means maintains an air space between the wall and the assemblythereby enabling convection air currents to dissipate the heat producedby the power supply.

8 Claims. 5 Drawing Figures MALE PLUG ASSEMBLY INCORPORATING POWERSUPPLY BACKGROUND OF THE INVENTION- The subject invention pertains, ingeneral, to power supplies which are incorporated at one end of a linecord together with a male plug which is adapted to be received in awall-mounted female receptacle; and, in particular. to an assemblyincluding a male plug, a power supply and means for preventing saidassembly from abutting the wall which includes the female receptacle soas to enable the passage of convection air currents between the wall andthe aforesaid assembly and thereby improve heat transfer from theassembly.

There are many applications where it is advantageous to incorporate asmall volume, light-weight power supply at one end of a line cordtogether with a male plug which is adapted to be received in awall-mounted female receptacle. For example, such a power supply may beincorporated in a conventional two, or three, conductor line cord at oneend of the line cord and assembled together with a male plug which isadapted for connection with a wall receptacle which supplies a singlephase. 60 hertz source of I volts. The power supply unit converts thesupplied phase. frequency and voltage to suit the appliance, orappliances. which are intended to be connected to the end of the linecord. The described assembly is often called a line cord power supply.The power supply is a small, compact, lightweight unit which is integralwith the line cord and is supported by the plug. The power supplyincludes heat dissipating circuit elements such as semiconductordevices, resistors, etc. Ordinarily, the male plug is inserted into awall-mounted female receptacle and the entire assembly, including thepower supply, abuts against the wall so that no air space is leftbetween the wall and the aforesaid assembly. As a result, a substantialsurface area of the aforesaid assembly is not available for transferringthe heat produced by the heat dissipating elements of the power supply.

SUMMARY OF THE INVENTION One object of the invention is to provide aline cord power supply assembly having improved heat transfercapabilities.

The aforementioned object, among others, is realized in accordance withone embodiment of the invention by the provision of a line cord powersupply comprising: a body of dielectric material; a power supplyenclosed in said body; a line cord electrically connected with saidpower supply and protruding from said body; at least two elongatedblades electrically connected with said power supply and protruding fromsaid body, said blades being adapted for being received in femalereceptacles for establishing a voltage between said blades; and, meanson said body for maintaining an air space between said body and saidfemale receptacles when said blades are received in said femalereceptacles.

In accordance with one feature of the invention, the aforesaid means formaintaining the air space is comprised of a plurality of fin memberswhich, in effect, increase the available cooling surface area of thedielectric body and also provide a plurality of separate passages forthe flow of convection air currents for the cooling of said dielectricbody.

In accordance with another feature of the invention, the aforesaid finmembers also provide bearing surfaces so as to limit movement of theelongated blades in the female receptacles when force is applied to thedielectric body.

Other objects, as well as other features and advantages of theinvention, appear hereinafter whereat two exemplary embodiments of theinvention are disclosed for the purpose of illustrating the invention;said disclosures including the accompanying drawing figures, the contentof which is hereinafter described.

DRAWINGS FIG. I is a block diagram showing the various electricalcomponents of which the subject line cord power supply is comprised.

FIG. 2 is a side elevation view showing a line cord power supply andmale plug assembly in accordance with a first embodiment of theinvention.

FIG. 3 is a plane view of the assembly of FIG. 2 taken along the line3-3 of FIG. 2.

FIG. 4 is a side elevation view showing another line cord power supplyand male plug assembly in accordance with a second embodiment of theinvention.

FIG. 5 is a plane view of the assembly of FIG. 4, taken along the line55' in FIG. 4.

DETAILED DESCRIPTION In the block diagram shown in FIG. I, the enclosurewithin the dotted lines [0 represents a body of dielectric material,such as, for example, synthetic rubber or plastic. Within the body 10there is embedded a line cord power supply which includes: an EMI filterI2; a first rectifier 14', an inverter 16; a step down transformer I8;another rectifier 20; another filter 22. A pair ofelectrically-conductive blades 24, 24 is electrically connected to theinput of the EMI filter I2, and, as shown in FIG. I, protrude from thebody [0. Also, a two-conductor line cord 26 is electrically connected tothe output of the filter 22 and. as shown in FIG. I, protrudes from thebody 10.

Although two blades 24, 24 are shown and although the line cord 26 isshown as having two conductors, it is to be understood that the assemblymay include more than two blades and the line cord may include more thantwo conductors.

The power supply comprising the components 12....22, within the body 10,includes such elements, or devices, as capacitors, resistors,semiconductor diodes, transistors, ferrite core members, etc. Theseelements, or devices, produce heat, to a greater or lesser degree, whenelectrically energized. It is important that the heat so produced bedissipated from these elements, or devices, in order to avoid damage tothe power supply, among other things.

In a first specific embodiment of the invention, illustrated at FIGS. 2and 3, the various components 12....22 of the line cord power supply areembedded in a molded body 10A of dielectric material. For example, thebody 10A may be molded from synthetic rubber or a suitable plastic.Protruding from the body 10A is a pair of blades 24, 24. The blades 24are electrically connected with an EMI filter I2 (not shown in FIGS. 2and 3) embedded in the body 10A. The molded body 10A includes a frontsurface 10B and a rear surface 10C, as shown in FIGS. 2 and 3. Integralwith and extending from the surface 108 for a distance of about half thelength of the blades 24, 24 are a pair of elongated members IOD ofdielectric material. The elongated members IOD coaxially encompasselongated portions of the blades 24 therewithin. As shown at FIGS. 2 and3, the end of each elongated member 10D is provided with a wide flangeportion IOE. Also integral with and extending from the surface IOB, asshown in FIGS. 2 and 3, are a plurality of fin members 10F. As shown,the protruding fin members 10F are spaced apart from each other alongthe surface 10B of the body IOA so that an air space exists betweenadjacent fin members IOF. Also, as indicated at FIG. 3, air spaces existbetween the adjacent elongated members 10]) and fin members IOF. Theaforementioned air spaces allow convection air currents to pass, amongother places, over the surface [08 of the body 10A. As a result,additional cooling of the body WA and the components 12....22 embeddedtherein is enabled. The advantages of the fins 10F and elongated members10D can be better appreciated by reference to FIG. 2. As shown at FIG.2, the blades 24 of the assembly are illustrated as being received insuitable female receptacles provided in a wall 28. As indicated, thewall 28 includes a surface 28A. With the blades 24 received in the female receptacles in the wall 28, the flanges 10E of the elongatedmembers 10D abut the wall surface 28A. Thus, the surface IOB of the body10A is separated by a distance L from the wall surface 28A. Beingseparated by the distance L convection air currents can pass, amongother places, over the surface 108 of the body IOA', i.e., theconvection air currents pass through the air spaces provided between thefin members 10F and between the elongated members 100 and fin members10F. With the construction shown in FIGS. 2 and 3, heat generated by theembedded components, I2...22, within the body IDA may be dissipated fromall of the exterior surfaces of the body [A. In prior art constructions,the front surface (i.e., the surface 108) would abut the wall surface28A such that no spacing (such as the distance L) would exist.Consequently, the whole surface IOB would be ineffective as a heatdissipating surface. Advantageously, the fin members 10F, as indicatedat FIG. 2, are almost the same height as the height of the front surface108. As a consequence, if the body [GA is twisted while the blades 24are in the receptacles in the wall 28, the end portions 100 of the finmembers 10F will come into contact with the wall surface 28A and preventthe further twisting of the body 10A. Therefore, as indicated at FIG. 2,the upper and lower end portions 100 serve as bearing surfaces in theevent that the body 10A should be twisted clockwise or counterclockwise.

A second specific embodiment of the invention is illustrated at FIGS, 4and 5. The embodiment illustrated at FIGS. 4 and is the same as theembodiment shown at FIGS. 2 and 3, except that fin members F are notemployed. Thus, like reference numbers are used in FIGS. 4 and 5 toidentify like elements and parts shown in the first embodimentillustrated at FIGS. 2 and 3. As indicated at FIGS. 4 and 5, when theblades 24 of the body 10A are received in a suitable female receptaclein the wall 28, a distance L separates the surface 100 of the body 10Cfrom the wall surface 28A. Thus, convection air currents may passbetween the surfaces 103 and wall surface 28A. The single flange 10B isenlarged, as compared with the embodiment shown in "FIGS. 2 and 3. Thesingle flange 10E bridges both members 10D, as shown in FIG. 5. Thesingle flange [0E provides a better bearing surface against wall surface28A.

While specific embodiments of the invention have been illustrated anddescribed in some detail to give examples of the invention, it is to beunderstood that the invention may be otherwise embodied withoutdeparting from the spirit and scope of the invention which ishereinafter defined in the claims.

What is claimed is:

I. In combination: a power supply, comprising means for converting aninput voltage to an output voltage having a different phase, frequencyor voltage therefrom, said power supply also including at least twogenerally parallel spaced-apart elongated blades adapted for being atleast partially received in a wall-mounted female receptacle whichestablishes said input voltage between said blades for energizing saidpower supply and a line cord having at least two conductors betweenwhich said output voltage from said power supply is established', a bodyof dielectric material within which said power supply including saidconverting means is enclosed, said blades protruding from a surface ofsaid body and said line cord protruding from said body at a locationremote from said surface; and, dielectric means extending from saidsurface of said body in the same general direction as said blades andenclosing part of the length of each blade so that an exposed length ofeach blade extends beyond said dielectric means, said exposed length ofthe blades being of sufficient length for receipt thereof in said femalereceptacle, said dielectric means spacing said surface of said body fromthe wall-mounted receptacle to enable convention air currents todissipate heat from said body.

2. The combination set forth in claim 1 wherein said dielectric meansincludes at least one rigid projecting flange extending from said meanswhere said means terminates and the exposed lengths of the blades beginand lying in a plane parallel to said body surface so that said flangeserves as a bearing surface in contact with the wall-mounted receptaclewhen said blades are received in said receptacle.

3. In combination: a power supply comprising heat producing elements andincluding at least two generally parallel spaced-apart elongated bladesadapted for being at least partially received in a wall-mounted femalereceptacle which establishes an input voltage between said blades forenergizing said power supply, said power supply also including a linecord having at least two conductors between which an output voltage fromsaid power supply is established; a body of dielectric material withinwhich said power supply including said heat producing elements areenclosed, said blades protruding from the surface of said body and saidline cord protruding from said body at a location remote from saidsurface; and, dielectric means extending from said surface of said bodyin the same general direction as said blades and enclosing part of thelength of each blade so that an exposed length of each blade extendsbeyond said dielectric means, said exposed lengths of the blades beingof sufficient length for receipt thereof in said female receptacle assaid surface of said body is maintained spaced from the wall-mountedreceptacle by said dielectric means to enable convection air currents tocool the surface of said body, said dielectric means including at leastone rigid, projecting flange where said means terminate and the exposedlengths of said blades begin so that said flange serves as a bearingsurface in contact with the wall-mounted receptacle when said blades arereceived in said receptacle; a plurality of parallel fin membersextending from said surface of said body coextensive with saiddielectric means and terminating at distances from said surface of saidbody short of said flange on said dielectric means, said parallel finmembers including between adjacent fin members air spaces for thepassage of convection air currents for cooling said surface of said bodyas well as the surfaces of said fin members.

4. The combination set forth in claim 3 wherein said fin members includebearing surfaces at extremities thereof which come into contact with thewall in which said female receptacle is mounted as said body is twistedand said blades in said female receptacle is rotationally moved.

5. The combination set forth in claim 1 wherein said dielectric means isintegral with said body of dielectric material.

6. The combination set forth in claim 5 wherein said dielectric means isbifurcated so that portions of each blade are separately enclosed tosaid means and a space for convection air currents is provided betweenthe enclosed blade portions.

7. In combination: a power supply comprising heat producing elements andincluding at least two generally parallel spaced-apart elongated bladesadapted for being at least partially received in a wall-mounted femalereceptacle which establishes an input voltage between said blades forenergizing said power supply, said power supply also including a linecord having at least two conductors between which an output voltage fromsaid power supply is established; a body of dielectric material withinwhich said power supply including said heat producing elements areenclosed, said blades pro truding from a surface of said body and saidline cord protruding from said body at a location remote from saidsurface; and, bifurcated dielectric means integral with said bodyextending from said surface of said body in the same general directionas said blade and enclosing part of the length of each blade so that anexposed length of each blade extends beyond said dielectric means and sothat portions of each blade are separately enclosed to said means and aspace for convection air currents is provided between the enclosed bladeportions, said exposed length of the blades being of sufficient lengthfor receipt thereof in a female receptacle as said surface of said bodyis maintained spaced from the wall'mounted receptacle by said dielectricmeans to enable convection air currents to cool said surface of saidbody; a plurality of parallel fin members extending from said surface ofsaid body coextensive with said bifurcated dielectric means andterminating at distances from said surface of said dielectric body shortof where the exposed blades begin, said fin members being integral withsaid dielectric body and including between adjacent fin members airspaces for convection air currents.

8. In combination: at least one heat-producing electrical circuitelement, comprising a resistor, semconductor device, capacitor.semiconductor diode, transistor, or ferrite core member; at least twogenerally parallel spaced-apart elongated blades electrically connectedwith said at least one circuit element, said elongated blades beingadapted for being received in a female receptacle mounted in the surfaceof a wall, said female receptacle being adapted for establishing aninput voltage between said elongated blades and energizing at least onecircuit element; a body of dielectric material within which said circuitelement is enclosed, said blades protruding from the surface of saidbody; and, means on said body for separating said surface of said bodyand said body from said wall when said blades are received in saidfemale receptacle so that convection air currents may cool substantiallythe en tire body.

i 1 I 1* l

1. In combination: a power supply, comprising means for converting aninput voltage to an output voltage having a different phase, frequencyor voltage therefrom, said power supply also including at least twogenerally parallel spaced-apart elongated blades adapted for being atleast partially received in a wall-mounted female receptacle whichestablishes said input voltage between said blades for energizing saidpower supply and a line cord having at least two conductors betweenwhich said output voltage from said power supply is established; a bodyof dielectric material within which said power supply including saidconverting means is enclosed, said blades protruding from a surface ofsaid body and said line cord protruding from said body at a locationremote from said surface; and, dielectric means extending from saidsurface of said body in the same general direction as said blades andenclosing part of the length of each blade so that an exposed length ofeach blade extends beyond said dielectric means, said exposed length ofthe blades being of sufficient length for receipt thereof in said femalereceptacle, said dielectric means spacing said surface of said body fromthe wall-mounted receptacle to enable convention air currents todissipate heat from said body.
 2. The combination set forth in claim 1wherein said dielectric means includes at least one rigid projectingflange extending from said means where said means terminates and theexposed lengths of the blades begin and lying in a plane parallel tosaid body surface so that said flange serves as a bearing surface incontact with the wall-mounted receptacle when said blades are receivedin said receptacle.
 3. In combination: a power supply comprising heatproducing elements and including at least two generally parallelspaced-apart elongated blades adapted for being at least partiallyreceived in a wall-mounted female receptacle which establishes an inputvoltage between said blades for energizing said power supply, said powersupply also including a line cord having at least two conductors betweenwhich an output voltage from said power supply is established; a body ofdielectric material within which said power supply including said heatproducing elements are enclosed, said blades protruding from the surfaceof said body and said line cord protruding from said body at a locationremote from said surface; and, dielectric means extending from saidsurface of said body in the same general direction as said blades andenclosing part of the length of each blade so that an exposed length ofeach blade extends beyond said dielectric means, said exposed lengths ofthe blades being of sufficient length for receipt thereof in said femalereceptacle as said surface of said body is maintained spaced from thewall-mounted receptacle by said dielectric means to enable convectionair currents to cool the surface of said body, said dielectric meansincluding at least one rigid, projecting flange where said meansterminate and the exposed lengths of said blades begin so that saidflange serves as a bearing surface in contact with the wall-mountedreceptacle when said blades are received in said receptacle; a pluralityof parallel fin members extending from said surface of said bodycoextensive with said dielectric means and terminating at distances fromsaid surface of said body short of said flange on said dielectric means,said parallel fin members including between adjacent fin members airspaces for the passage of convection air currents for cooling saidsurface of said body as well as the surfaces of said fin members.
 4. Thecombination set forth in claim 3 wherein said fin members includebearing surfaces at extremities thereof which come into contact with thewall in which said female receptacle is mounted as said body is twistedand said blades in said female receptacle is rotationally moved.
 5. Thecombination set forth in claim 1 wherein said dielectric means isintegral with said body of dielectric material.
 6. The combination setforth in claim 5 wherein said dielectric means is bifurcated so thatportions of each blade are separately enclosed to said means and a spacefor convection air currents is provided between the enclosed bladeportions.
 7. In combination: a power supply comprising heat producingelements and including at least two generally parallel spaced-apartelongated blades adapteD for being at least partially received in awall-mounted female receptacle which establishes an input voltagebetween said blades for energizing said power supply, said power supplyalso including a line cord having at least two conductors between whichan output voltage from said power supply is established; a body ofdielectric material within which said power supply including said heatproducing elements are enclosed, said blades protruding from a surfaceof said body and said line cord protruding from said body at a locationremote from said surface; and, bifurcated dielectric means integral withsaid body extending from said surface of said body in the same generaldirection as said blade and enclosing part of the length of each bladeso that an exposed length of each blade extends beyond said dielectricmeans and so that portions of each blade are separately enclosed to saidmeans and a space for convection air currents is provided between theenclosed blade portions, said exposed length of the blades being ofsufficient length for receipt thereof in a female receptacle as saidsurface of said body is maintained spaced from the wall-mountedreceptacle by said dielectric means to enable convection air currents tocool said surface of said body; a plurality of parallel fin membersextending from said surface of said body coextensive with saidbifurcated dielectric means and terminating at distances from saidsurface of said dielectric body short of where the exposed blades begin,said fin members being integral with said dielectric body and includingbetween adjacent fin members air spaces for convection air currents. 8.In combination: at least one heat-producing electrical circuit element,comprising a resistor, semconductor device, capacitor, semiconductordiode, transistor, or ferrite core member; at least two generallyparallel spaced-apart elongated blades electrically connected with saidat least one circuit element, said elongated blades being adapted forbeing received in a female receptacle mounted in the surface of a wall,said female receptacle being adapted for establishing an input voltagebetween said elongated blades and energizing at least one circuitelement; a body of dielectric material within which said circuit elementis enclosed, said blades protruding from the surface of said body; and,means on said body for separating said surface of said body and saidbody from said wall when said blades are received in said femalereceptacle so that convection air currents may cool substantially theentire body.